• Title/Summary/Keyword: frost action

Search Result 31, Processing Time 0.031 seconds

Stiffness change measurement for subgrade soils at freezing and thawing using impact resonance test (충격공진시험을 이용한 노상토의 동결.융해시 강성도 변화 측정)

  • Lee, Jae-Hoan;Kweon, Gi-Chul
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2009.03a
    • /
    • pp.686-691
    • /
    • 2009
  • Damage due to frost action in pavement structure system is creating either frost heave or stiffness-weakening of subgrade soil follow melting. The formation of ice lenses requires a frost-susceptible soil, freezing temperatures, and continuous water supply. Eliminating one of these conditions suffices to significantly reduce the intensity of frost action. It is important to know characteristics of subgrade soil in frost susceptibility or decide degree of freezing permission. Also, study on the stiffness variation of subgrade soil during freezing and thawing cycle is very important. In this study, Impact resonance test for subgrade soil at freezing and thawing confirms that is applied for.

  • PDF

Development of Prediction Model of Frost Penetration Depth on Pavement in Korea (포장도로의 실측값을 활용한 한국형 동결깊이 예측모델 개발)

  • Hong, Seung-Seo;Kim, Young-Seok;Kim, Hak-Seung
    • Journal of the Korean Geosynthetics Society
    • /
    • v.9 no.3
    • /
    • pp.47-56
    • /
    • 2010
  • Korea is known to have seasonal frozen ground during a winter season due to climatic and ground conditions. Temperatures below $0^{\circ}C$ cause pavement failure by frost heaving and thaw settlement. A frost protection layer has been constructed in pavements to avoid damage caused by frost action. Anti-frost design methods in Korea have been adopted, which is established in U.S. and Japan. However the characteristics of soils in Korea are different and there are no reasonable modifications to accommodate these characteristics. Therefore, adequate pavement design procedures including seasonal frost action, as well as construction and maintenance practices are required. In this paper, the frost penetration depths along national roads in Korea are presented based on field measurement over several years (1991~2010). The frost penetration depths are analyzed with respect to the Provinces of Korea and sunny/shaded areas.

  • PDF

A Numerical Analysis on the Characteristics of Frost Heaving at Road Pavement in Korea (국내 도로포장의 동상 특성에 대한 수치해석적 연구)

  • Kweon, Gi-Chul;Oh, Se-Boong;Kim, Hyung-Bae;Choi, Chang-Gyu
    • International Journal of Highway Engineering
    • /
    • v.5 no.2 s.16
    • /
    • pp.37-47
    • /
    • 2003
  • The basic study was performed on the mechanical analysis of frost and heave using program FROST by CRREL, U.S. army corps of engineers. The characteristics of frost heaving in pavement was analyzed by considering climate, pavement sections and subgrade soil conditions in Korea. Water tables were located at the depth of 0.35m, 2m and 3.35m from subgrade. Inputs were evaluated inevitably from the existing references. As a result frost heave and depth were evaluated with respect time. Maximum frost heave decreased lowering the water table and maximum frost depth was less than 15cm from subgrade. Frost action did not affect seriously on the analysis sections.

  • PDF

Analysis of Penetration Depths in Pavement in Korea (포장도로에서의 동결심도 조사분석)

  • Kim, Young-Chin;Hong, Seung-Seo
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2005.03a
    • /
    • pp.475-482
    • /
    • 2005
  • Many public facilities including roadway, railway, and embedded pipe lines in this country have been damaged by the repeated freezing and thawing of the soil during winter and spring every year. However, there are only few research results in field of frozen ground in this country. Also, there are no the formulation of the reasonable equation for frost penetration depths and of the criterion for identifing potentially frost-susceptible soil in design manual of pavement yet. Through this study it is anticipated to asses the frost action problem in roadway, railway, and water suppply lines and to establish the design criterion about pavement in seasonal cold region.

  • PDF

Frost Heave Force of Ground and Countermeasure for Damage of Structures (지반의 동상력과 구조물의 피해대책)

  • Rui, Da-Hu;Teruyuki, Suzuki;Kim, Young-Su
    • Journal of the Korean Geotechnical Society
    • /
    • v.23 no.5
    • /
    • pp.43-51
    • /
    • 2007
  • Frost action may cause extensive damage to building, structures, roads, railways and utility lines in seasonal frost. The research about frost heave of natural ground has been considerably performed. In late years various structures have become complicated with the development of social infrastructure maintenance. Therefore countermeasure to frost heave becomes a matter of great importance from a new viewpoint. This study was aimed at catching natural ground frost heaving force quantitatively. Frost heaving forces on circular steel plates which were set on ground surface were measured in field test. The frost heaving forces arise at freezing front propagates to the structures through frozen soil layer. Besides, a full scale model of multi-anchored retaining wall was installed in field, and the freezing lines, frost heave pressure to act on a wall block, and so on were measured. Finally, the position and shape of frost line were estimated by using numerical simulation and a method to determine replacement range was suggested with soil properties and weather data.

Geotechnical Characteristics of Frost-Susceptibility Soil Using Modified Freeze-Thaw Apparatus (변형된 동결-융해 시험장치를 이용한 동상민감성흙의 지반공학적 특성)

  • Shin, Eun-Chul;Ryu, Byung-Hyun;Park, Jeong-Jun
    • Journal of the Korean Geosynthetics Society
    • /
    • v.8 no.1
    • /
    • pp.53-59
    • /
    • 2009
  • A new system of modified freeze-thaw testing apparatus is introduced. This system is developed to evaluate the geotechnical parameters and their dependence upon freezing-thawing history of frost-susceptibility soil. A necessary condition for stationary frost heaving is clarified in this paper. The method changes the thermal boundary condition up to the net heat flow at the freezing frost becomes zero. The effectiveness of this method is verified by freeze-thaw tests. Frost heaving observed after the application of the method is found to be due to another frost heaving action called long-term frost heaving. This frost heaving has already been studied and is considered ignorable as engineering factor because of its small heaving amount.

  • PDF

A Study on the Freeze-Thaw Resistance of Planting Concrete Using Recycled Aggregate (재생골재를 이용한 식재용 콘크리트의 동결융해저항성에 관한 연구)

  • 이상태;전충근;김경민;최청각;한천구
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2003.05a
    • /
    • pp.233-236
    • /
    • 2003
  • This study is intended to investigate the resistance of frost damage of concrete for planting, which recycled aggregate is used, by freezing in air and thawing in water. According to the results, if AE agent of 0.005% is mixed in making concrete for planting, it is thought that the resistance of frost damage is guaranteed in winter because concrete for planting is not under severe freezing and thawing function, but under natural weather action.

  • PDF

The Relationship Between Freezing Index and Frost Penetration Depths in Korea National Road (동결지수와 전국 포장국도에서 실측한 동결깊이의 관계)

  • Kim, Youngchin;Hong, Seungseo
    • Journal of the Korean GEO-environmental Society
    • /
    • v.10 no.4
    • /
    • pp.15-24
    • /
    • 2009
  • Korea is known to have seasonal frost during winter and the effect of low temperatures and water may cause a weakening of pavements. For that reason, frost protection layers have been constructed in pavements to avoid damage caused by frost action. The practies established in USA and Japan have been adopted as anti-frost design methods in Korea. However, the characteristics of Korean soils are different. Additionally, there is no formulation of a reasonable equation for frost penetration depth and the criterion to identify potentially frost-susceptible soils in present pavement design manuals in Korea. Therefore, adequate pavement design procedures in seasonal frost areas, as well as construction and maintenance practices are required. In this paper, frost penetration depths along national roads in Korea were measured and analyzed over several years. The frost penetration depth was analyzed with respect to the provinces of Korea and sunny/ shaded areas. Additionally, measurement results were compared to the formula of the US Army Corps of Engineers and Ifukube in Japan.

  • PDF

An Experimental Study on the Resistance of Concrete Included Rice Husk Ash Against Rapid Freezing and Thawing (왕겨재를 혼입한 콘크리트의 동결융해 저항성에 관한 실험적 연구)

  • 이준구;박광수;이응찬;김한중
    • Proceedings of the Korean Society of Agricultural Engineers Conference
    • /
    • 1999.10c
    • /
    • pp.294-300
    • /
    • 1999
  • After researching the physical properties of the concrete included Rice Husk Ash(RHA concrete) and workability of fresh concrete admixed RHA, we have tested durability of RHA-concrete against freeaing and thawing in the winter using rapid freezing and thawing test method(KS F 2456) . There aretwo hypotheses to explain the failure mechanism of a freezing and thawing action. First, the hydraulic pressure in the pores of freezing concrete make an internal stress of concrete structures outbreaking micro crack in the face of concrete, Second, Frost action causing damage to cement paste repeatedly come from soil frost action, freezing water in the capillaries. Initial Relative Dynamic Modulus of Elasticity (DME) was biggest in cae of unit binder weight 600kgf/㎥ and relative dynamic modulus of elasticity increased until 300cycles. In general , initial relative DME was proportional to unit binder weight . Relative DME was decreased in proportion to unit binder weight in the case of 300, 400, 500kgf/㎥ , but relative DME fo the others remained more than 90% until 300 cycles. It was not good effect of intermixed RHA to concrete in case of below unit binder weight 300kgf/㎥ and the resistance of freezing and thawing was not good either.

  • PDF

The Frost Heaving Characteristics of Subgrade Soils Using Laboratory Freezing System (실내동결시스템을 이용한 노상토의 동상 특성)

  • Shin, Eun-Chul;Ryu, Byung-Hyun;Park, Jeong-Jun
    • International Journal of Highway Engineering
    • /
    • v.12 no.2
    • /
    • pp.71-79
    • /
    • 2010
  • The influence of fines of the frost susceptibility of subgrade soils were established by laboratory freezing system test simulating closely the thermal conditions in the field. During the winter season, the climate is heavily influenced by the cold and dry continental high pressure. Because of siberian air mass, the temperature of January is $-6{\sim}-7^{\circ}C$ on average. This chilly weather generate the frost heaving by freezing the moisture of soil and damage potential of the road structure. In the freezing soil, the ice lenses increase the freeze portion of soil by absorbing the ground water with capillary action. However, the capillary characteristics differ from the sort of soil on the state of freezing condition. In the current design codes for anti-freezing layer, the thickness of anti freezing layer is calculated by freezing depth against the temperature condition. Therefore, they have a tendency of over-design and uniform thickness without the considerations of thermal stability, bearing capacity and frost susceptibility of materials. So, it is essential for studying the appropriateness and bearing capacity besides the seasonal and mechanical properties of pavement materials to take a appropriate and reasonable design of the road structure. In this Paper, the evaluation of frost susceptibility was conducted by means of the mechanical property test and laboratory freezing system apparatus. The temperature, heaving amount, heaving pressure and unfrozen water contents of soil samples, the subgrade soils of highway construction site, were measured to determine the frost susceptibility.